use R6 class; remove data first and last elements --> simplify
-rw-r--r-- 98 .gitattributes
-rw-r--r-- 51 .gitfat
-rw-r--r-- 199 .gitignore
-rw-r--r-- 1836 NOTES
-rw-r--r-- 334 README.md
drwxr-xr-x - data
drwxr-xr-x - pkg
drwxr-xr-x - reports